Question

例如，我有一个包含名称的列表，我想查看这些名称是否已经存在于会议室数据库中，或者名称是否已更改。如果还没有，则保存否则替换。问题是我的逻辑必须保留在存储库中，直到正确的名称保存在room db中，然后在我的活动中观察它或在recyleradapter中显示它。到目前为止，我已经完成了使用AsyncTask添加对象列表的操作，但是使用AsyncTask检索了对象列表（名称）并在存储库中操作该数据到目前为止还不是很幸运。也许使用onPostExecute，然后将结果发送回存储库？

房间：

$request->ip()

AsyncTask：

@Dao
public interface NewUsersDao {

    @Insert
    long[] addNewUsers(NewUsersModel... newUsers);

    @Query("SELECT DISTINCT * FROM  search_users")
    LiveData<List<NewUsersModel>> readAllUsersFromSQL();
}

存储库：

public class InsertAsyncTask extends AsyncTask<NewUsers, Void, Void> {

    private NewUsersDao mNewUsersDao;

    public InsertAsyncTask(NewUsersDao newUsersDao) {
        mNewUsersDao = newUsersDao;
    }

    @Override
    protected Void doInBackground(NewUsers... newUsers) {
        mNewUsersDao.addNewUsers(newUsersModels);
        return null;
    }

}

ViewModelclass：

public static NewUserRepository getInstance(Context context){
    if(repository == null){
        repository = new NewUserRepository(context);}
}
return repository;

public NewUserRepository(Context context) {
    mNewUsersDatabase = NewUsersDatabase.getInstance(context);}

for(final NewUsers namesObject: mNameList){
    addUserToSql(namesObject) }

public void addUserToSql(NewUsers names){
     new InsertAsyncTask(mNewUsersDatabase.getNewUsersDao()).execute(names);}

public LiveData<List<NewUsers>> readAllUsersFromSQL(){
    return mNewUsersDatabase.getNewUsersDao().readAllUsersFromSQL();}

活动：

@RequiresApi(api = Build.VERSION_CODES.N)
public class NewUsersViewModel extends AndroidViewModel {

    private static final String TAG = "NewUsersViewModel";
    private NewUserRepository mNewUserRepository;


    public NewUsersViewModel(@NonNull Application application) {
        super(application);
        mNewUserRepository = NewUserRepository.getInstance(application);}

    public LiveData<List<NewUsersModel>> readAllUsersFromSQL(){
        return mNewUserRepository.readAllUsersFromSQL();}
}

如何在存储库中检索房间查询结果

0 个答案: